Back frame in shaped plywood joined to the seat frame. Seat sprung system with twisted elastic belts. Upholstery in leather or fabric. Seat padding in polyurethane foam. Internal part of the back in polyurethane foam and acrylic fibres, parts padded individually. External part equipped with a 10 mm layer of polyurethane. Base in polished stainless steel with 5 laser-finished spokes, 8 mm in width, with aluminium turnings and chrome wheels, available in the metal finishing selection.